Answer:
A. 97.8 mm
Explanation:
There are 10 divisions between 9 cm (90 mm) and the end of the ruler (10 cm or 100 mm).
Each division equals 1 mm.
Each 5 mm mark has a longer tick, and the dashed red line is between the 97 mm and 98 mm marks.
You would normally estimate to the nearest tenth of a division. An estimate of 0.8 mm is reasonable.
The length of the object is 97.0 mm + 0.8 mm = 97.8 mm.
B is wrong. You can't possibly estimate to the nearest hundredth of a division.
C is wrong. The dashed red line slightly before the 98 mm mark.
D is wrong. If the dashed red line were exactly on the 98 mm mark, you would record the measurement as 98.0 mm. This indicates that you measured the object to zero tenths on either side of the mark.
Answer:
it doesnt even give you enough information for you to answer it
Explanation:
Answer:
B
Explanation:
Recall the law of effusion:

Because 5 mol of oxygen was effused in 10 seconds, the rate is 0.5 mol/s.
Let the rate of oxygen be <em>r</em>₁ and the rate of hydrogen be <em>r</em>₂.
The molecular weight of oxygen gas is 32.00 g/mol and the molecular weight of hydrogen gas is 2.02 g/mol.
Substitute and solve for <em>r</em>₂:

Because there are 5 moles of hydrogen gas:

In conclusion, it will take about 2.5 seconds for the hydrogen gas to effuse.
Check: Because hydrogen gas is lighter than oxygen gas, we expect that hydrogen gas will effuse quicker than oxygen gas.
2 and a half
250 x 2 =500
250/2=125
and 125 is a half of 250
so your answer is
2 and a half
I think the answer is C but don’t quote me on that